reidentify: poor features centering in non-interactive mode?

Vallery Stanishev wrote on Feb 06, 2008

Hello,

I am reducing a large number of spectra with the same set-up. I am using reidentify in non-interactive mode to do the wavelength solutions. It works fine but I was not very happy with the RMS I get. Then I noticed that some features were obviously no well centered by reidentify. Running reidentify interactively and using "a"+"c" keys to re-center all features improved the RMS significantly and the lines that were not centered well before are now OK. I am wondering what could be the reason for this? Is there any way to get around this problem?

This the command that I use in my script. In the IDENITLY I use "niter=3" with 3sigma clipping.

reidentify ("arc_fid",
"@arc_std_sl1.5.txt", "yes", "1", "1", interactive="yes", section="middle line",
newaps=yes, override=no, refit=yes, trace=no, step="10", nsum="10",
shift="INDEF", search=INDEF, nlost=0, cradius=15., threshold=0.,
addfeatures=no, coordlist=" linelists$idhenear.dat", match=3.,
maxfeatures=1000, minsep=2., database="database", logfiles="logfile",
plotfile="", verbose=yes, graphics="stdgraph", cursor="", aidpars="")

Thank you very much.

Best,
Vallery

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Vallery Stanishev wrote on Feb 06, 2008

Hello,

I figured it out. Need to use cursor command file and interactive mode:

cursor file:

0 0 1 a
0 0 1 c
0 0 1 f
0 0 1 q
0 0 1 q

print("yes") | reidentify ("arc_fid",
"arc", "yes", "1", "1", interactive="yes", section="middle line",
newaps=yes, override=no, refit=yes, trace=no, step="10", nsum="10",
shift="INDEF", search=INDEF, nlost=0, cradius=10., threshold=0.,
addfeatures=no, coordlist=" linelists$idhenear.dat", match=3.,
maxfeatures=1000, minsep=2., database="database", logfiles="logfile",
plotfile="", verbose=yes, graphics="stdgraph",
cursor="cursor.cur", aidpars="")

It would not work on file lists, though:

print("yes") | reidentify ("arc_fid", "@arc", "yes", "1", "1", .....)

would do it only on the first file in the list

Anyway, I went back to the refernece file and imroved the wavelength solutiion with IDENTIFY. To do that I also needed to re-center the features with "a"+"c". This improved the RMS. It seems that marking features with "m" and then adding more features with "l" is sensitive to the stating point for the centering and one always need to re-center with "a"+"c". With this improved reference file, the performance of REIDENTIFY also improved.

/Vallery

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Last post on Feb 06, 2008